Various prior art sealing systems are shown in U.S. Pat. Nos. 6,027,125, 5,433,183, 5,232,252, 4,552,385, 4,456,288, 3,837,687, 3,779,564, 3,680,874, 3,447,819, 3,185,504, 2,922,665, 2,840,350, 2,839,089, and 2,430,445.